16 FOSSIL ECHINI OF THE WEST INDIES. 



does not show completely the distal tip as figured by Cotteau. It 

 may have been broken at the tip. This species is known only from 

 primary spines, and Cotteau mentions another specimen besides the 

 one he figured, presumably in the Cleve collection. The Washington 

 specimen compared with spines of melitensis shows that in anguillce 

 the ornamenting spinelets are higher, larger, and more alternating 

 in rows than are those of melitensis. As the spines of Cidaris clevei, 

 which occurs in the same formation and island, are unknown, it may 

 be that these spines should be referred to that species; but of this 

 there is no certainty. Guppy referred both Cidaris clevei and anguillce 

 to melitensis as synonyms. It seems that he was quite mistaken in 

 the case of anguillce, and in the case of clevei the conclusive evidence 

 is wanting. 



Oligocene, Anguilla formation, island of Anguilla, Guppy collection 

 ex Cleve, cotype, one spine, and indeterminable fragments of other 

 spines on a small slab, U. S. Nat. Mus. No. 115393. Cotteau mentions 

 a second spine of the same size, but it was not found in the Guppy 

 collection. It is of course possible that the Washington specimen 

 is this second spine referred to. 



Cidaris peloria, 1 new species. 

 (Plate 1, Figures 2 to S.) 



The following is a description of this species : 



Known only from primary spines and a single interambulacral plate. 

 There are numerous primary spines, none of which, however, is complete 

 both distally and proximally. Spines massive, circular in section, tapering 

 gradually from just above the milled ring to the tip, which ends bluntly. 

 Smooth throughout the length, excepting near the tip, where there are a 

 few, 7 to 10, low, ridged plications, the longest of these being about IS mm. 

 in extent. In a few spines, which are presumably from the ventral side, 

 the distal plications are more strongly pronounced, and there is a rounded 

 median spinelet given off from the distal end of the spine. The largest 

 single fragment measures 59 mm. in length and 8 mm. in diameter at the 

 widest part. Another fragment, somewhat shorter but of greater thickness, 

 measures 9 mm. in diameter. Putting fragments together and allowing 

 for the angle of tapering of the spine, as in plate 1, figure 5, a complete 

 large spine must have measured at least from 100 to 120 mm. in length. 

 The single interambulacral plate, which is apparently from the middle or 

 ventral side of the test, has a high, rounded, perforate mammelon, wide 

 scrobicular area, and relatively narrow row of marginal secondary tubercles. 

 The plate measures 15 mm. in width and 10 mm. in height, 13 mm. in width 

 on the horizontal suture line where it came in contact with the next adjacent 

 interambulacral plate in the vertical series. 



This species evidently was very large, but there is not the evidence 

 for making any close estimate of its size ; however, comparing the single 

 interambulacral plate with W. B. Clark's figure of the Cretaceous 



1 7f (Xwpios = huge, gigantic. 



